How to Read Sewing Thread Counts Like 20S/2 and 40S/2

Breaking Down the S and the Slash

When a count is shown as 20S/2 the letter S points to the English cotton count of the single yarn and the figure after the slash tells you how many singles are folded into one thread. A bigger first number signals a finer single, which is why 40S/2 threads run lighter than 20S/2. Both counts here are two ply constructions, so they feed steadily through a lockstitch head.

Choosing 40S/2 for Light and General Seaming

40S/2 suits the finer end of production: shirts, thobes, abayas and clean topstitching on collars and cuffs. It holds the seam without ridging the fabric. We supply it on a 3000 yard cone carrying 84 g of net thread, and on a longer 5000 yard cone carrying 140 g net, so long runs need fewer cone changes per colour.

100% Polyester Sewing Thread 40/2 X 3000 Yards

Choosing 20S/2 for Loaded Seams

20S/2 is the coarser thread of the pair and belongs on work that gets stressed: uniform trousers, outerwear, heavy bags. Our version comes as a 2370 yard cone holding 132 g of net thread weight, ready to plan kilos per colour against your stitch consumption.

Polyester Sewing Thread 20S/2 x 2370 Yards

Matching Count to Needle Before Tension

Set the count from the operation first. A heavy thread in a small needle groove shreds and skips; a fine thread on heavy fabric fails to bite. Once the count is fixed, pick the needle to suit it and only then balance the tension. Swapping count mid-run without changing the needle is a frequent trigger for stitch skips.

Using Net Thread Weight to Check Quotations

Thread is sold by the kilo per colour but consumed by the metre, and the net thread weight on the cone is what lets you move between the two. With 84 g, 132 g and 140 g published for our put-ups you can convert yardage to weight and weigh a random cone to verify it.

100% Polyester Sewing Thread 40/2 X 5000 Yards